Hitomi – Little Bits of Science

And Hitomi is Gone Again. For Good.

So just after I made the last post about a potential save of the Hitomi X-ray telescope, news comes that the satellite is gone for good this time. Due to a software error, the telescope was sent spinning out of control until it basically tore itself apart. Sadly, this 10-year planned mission ended up giving only a few days of data collection.

At 3:01 a.m. Japan time on March 26, the spacecraft began a preprogrammed manoeuvre to swivel from looking at the Crab Nebula to the galaxy Markarian 205. Somewhere along the way, the problems with the star tracker caused Hitomi to rely instead on another method, a set of gyroscopes, to calculate its orientation in space. But those gyroscopes were reporting, erroneously, that the spacecraft was rotating at a rate of about 20 degrees each hour. Tiny motors known as reaction wheels began to turn to counteract the supposed rotation.

Hearing from Hitomi Again!

So earlier in the life of Little Bits of Science, I wrote about the Hitomi satellite, at the time apparently lost in space. It turns out that the day after I wrote about it, Hitomi was heard from again!

Junked? Maybe not. Hitomi, a Japanese astronomy satellite, was thought to be lost after it failed to come online. Now the Japanese Aerospace Exploration Agency says the satellite has phoned home – but a full recovery will take months.

What does this mean, exactly? Well, it’s too early to say, even now a month since we’ve heard from the satellite. According to communication that scientists have since gathered from Hitomi – infrequent beacon signals which have been picked up – it appears the satellite is still there, just spinning out of control. And apparently, this is a recoverable situation. The Japanese space agency responsible for the satellite is working on restoring communication and stabilizing it so Hitomi can return to its mission of X-Ray observation of the universe.

What Happened to the Hitomi Telescope?

Launched on February 17th, the Hitomi telescope is an X-Ray telescope commissioned by the Japanese Aerospace Exploration Agency (JAXA). While everything looked fine for the telescope during testing done since launch, when it was time to power up for real work this past Sunday, the satellite was strangely quiet.

Engineers have been unable to determine the health of the satellite since the sudden disruption in communications, JAXA said, although ground controllers received a brief signal from Hitomi.

Shortly after the go-live time, the US Joint Space Operations Center, which tracks space debris, picked up 5 objects orbiting near where the satellite was or was supposed to be. Work is now underway to determine what happened to the Hitomi, as well as to see if the 3-year mission can be salvaged or not.

Whatever the cause of the problem, don’t count Hitomi out yet. “The interesting thing about the Japanese is they tend to be very good at resurrecting things that would otherwise be dead,” says Jah. For instance, JAXA recently maneuvered the Akatsuki satellite into orbit around Venus, after the probe had been adrift in space for five years.